@Luna_MariaTo answer your first post;
That could certainly happen. There would be scout vessels, sent beyond the territories to explore all of space. It wouldn't be surprising if a few of those had been lost over the years, perhaps having been expected to jump straight into a system with a black hole or whatever. It wouldn't be too hard for a scout vessel to be overwhelmed, captured, and sent back under the control of the Zerg.
Now, the second point, they way they
could turn them into slaves if you played it well enough, IE enough that I would believe to my race's extent that they'd fall for it. Let's say there is this alien species or something that the Zerg finds too strong. The Zerg could play it off that the aliens they are fighting somehow threaten the beliefs of the Zenohunts, etc etc.
That, or the Zerg could somehow play it off that they came
from the Zenohunt gods, though this would be harder to do however would yield the Zerg a powerful, loyal ally, until Zenohunts found the truth out somehow or didn't start to believe the Overmind any more.
To your second post;
Sure, open up a PM with me whenever ready.